Abiotic Depletion Potential - · PDF fileLeiden University. The university to discover. Abiotic Depletion Potential - its philosophy from 1995 / 2002 – Jeroen Guinée Metals Industry

Leiden University. The university to discover.

Abiotic Depletion Potential

- its philosophy from 1995 / 2002 –

Jeroen Guinée

Metals Industry Workshop on “Mineral resources in LCIA”

Natural History Museum, London, 14 October 2015


Contents

• The ADP 1995/2002

– philosophy, definitions & choices made

– based on Guinée & Heijungs 1995 and van Oers et al.

2002

• Recent developments

• Conclusions

Contents


Sources

Contents

http://www.leidenuniv.nl/cml/ssp/projects/lca2/report_abiotic_depletion_web.pdf


Core issue addressed by ADP

• How serious is the depletion of one particular

natural resource in relation to that of another,

and how can this be expressed in terms of

characterization factors for these resources?

– A typical LCA question: how does an aluminum

beverage can compare to a PET or glass bottle with

respect to depletion of resources?

The ADP 1995/2002


No scientifically „correct‟ method

• Abiotic depletion is a problem crossing the

economy-environment system boundary

– reserve depends on (future) technology

– is it an economic or environmental problem, or both?

• Depletion problem can‟t be verified empirically:

– „correct‟ definition of the problem

– total amount of resource

– result of depletion equation

can all not be validated empirically

The ADP 1995/2002


Decisions/choices to take/make when

developing a method for depletion

• Abiotic and biotic

• Definition of the problem

• Stocks (deposits), funds and flows

• Renewable and non-renewable

• Concepts for assessing depletion

• Definition of availability

• Type of reserves

• Equation(s) for characterization factors (CFs)

The ADP 1995/2002


Abiotic and biotic

• ADP: assess depletion of biotic resources

separately from abiotic resources

– because of the intrinsic value of biotic resources, their

source function and their role in the maintenance of

the life support system

– the weighting step of impact assessment provides an

opportunity to assign a different significance to biotic

depletion

• Focus in this presentation on abiotic resources

The ADP 1995/2002


Definition of the problem

• Many possible definitions exist:

A. decrease of resource itself

B. decreasing world reserves of useful energy/exergy

C. contribution of current extraction processes to other

impact categories (no separate impact category)

D. incremental change in environmental impact of

extraction processes at some point in future (e.g.

result of having to extract lower-grade ores or

recover materials from scrap)

E. no environmental but economic problem

F. Etc.

The ADP 1995/2002


Definition of problem

• ADP: „decreasing availability of natural resources

(in geosphere and/or anthroposphere)‟

– „abiotic resources‟: natural resources (including fossil

energy resources and minerals) which are regarded as

non-living

– resource depletion is an environmental problem in its

own right, while recognizing that views differ on this

– problem definition highly subjective -> no „perfect‟

method, no scientific consensus ….

The ADP 1995/2002


Looking back … ADP only

addresses „depletion‟

• Depletion of a resource means that its amount

present on earth is being reduced. It refers to

geological/natural stocks

• Scarcity of a resource means that the amount

available for use is, or will soon be, insufficient

(“demand higher than supply flow”)

• Criticality of a resource means that it is scarce

and at the same time essential for the present

society

Source: Van der Voet (2013)


Definition of problem

• ADP: „decreasing availability of natural

resources‟

– „abiotic resources‟: natural resources (including

fossil energy resources and minerals) which are

regarded as non-living

The ADP 1995/2002

„Depletion‟ only!


Stocks, funds and flows

• Stocks/deposits: resources not regenerated

within human lifetimes: fossil fuels, minerals, etc.

• Funds: resources regenerated within human

lifetimes: groundwater and soil

• Flows: resources constantly regenerated: wind,

river water & solar energy (competitive use)

• ADP: focus on stocks

The ADP 1995/2002


Renewable, non-renewable

• Commonly made distinction

• ADP: renewability (or regeneration) is parameter

in modeling of CFs rather than a criterion for

categorizing resource types

– comparable with the distinction between degradable

and non-degradable toxic substances.

The ADP 1995/2002


Concepts for assessing depletion

• What determines the „decreasing availability” of

a given resource?

• Concepts for quantifying availability:

– the amount available (the reserve)

– annual de-accumulation: annual production (e.g. in

kg/yr) minus annual regeneration (same unit)

The ADP 1995/2002

We also touched upon aspects of

scarcity/criticality (e.g., substitution)

but didn‟t include these in the ADP;

still „depletion‟ only!


Concepts: depletion measured by

economic data (e.g., price)

• Although the price of a resource can be

considered as a measure of its scarcity and

societal value, it reflects more than just that:

– structure of particular economic markets

– national social conditions reflected in labour cost

– power of mining companies with a monopoly

– identification of new reserves is very expensive

– etc.

The ADP 1995/2002

Leiden University. The university to discover. The ADP 1995/2002


Concepts: physical data

• Physical data on reserves (“resources”) & de-

accumulation

• ADP: physical data on reserves & de-

accumulation; substitution not (yet) possible

The ADP 1995/2002


Definition of availability

• „Narrow sense‟: availability in primary extraction

medium

– depletion: annual production exceeds annual regeneration

• „Broad sense‟: availability in geo- and anthroposphere

– elemental materials can never be depleted unless ..

competitive use rather than depletion

– increasing energy & solid waste amounts in extracting ever

lower concentrations, or in recovering dispersed resources

• ADP: „narrow sense‟

– while recognizing „broad sense‟ is preferable (this afternoon)

The ADP 1995/2002

„Urban‟/anthropogenic stocks


Type of reserves

• Reserve base: reasonable potential for becoming economically and technically available

• Economic reserve: part of reserve base which could be economically extracted at time t

• Ultimate reserve: natural resources in earth crust

• Ultimately extractable reserves: reserves that can ultimately be technically extracted

The ADP 1995/2002

Mineral resource

Mineral reserve

Crustal content

Extractable global resource

Resource …confusion


Earth crust volume (m3; average crust thickness of

17000 m and crust surface of 5.14x1014

m2)

Co

nce

ntr

atio

n (

kg/m

3)

Ultimately extractable reserve

Ultimate reserve

Reserve base

Economic reserveNo longer reported by USGS

Ultimately extractable reserves

best but unknown by definition

Economic and base reserves involve

economic considerations not directly

related to resource depletion

ADP: „ultimate reserves‟ second best yardstick,

but sensitivity analyses recommended with

other reserves!!

Extractable global resource

Mineral resource

Crustal content

Mineral reserve

The ADP 1995/2002


Equation: R and/or DR rate

• A and B differ only in scale of their Rs – depletion of B more serious problem than A

• C and D differ only in scale of their DRs – extraction of 1 kg C more problematical than 1 kg of D

• Conclusion: both R and DR important – Another argument derives from renewable resources: seriousness of

extracting renewable resource is determined partly by degree of net de-accumulation (production/extraction minus regeneration)

resource

A

B

C

D

Reserve (Gton)

1

0.0001

1

1

De-accumulation Rate (Gton/yr) 0.000001

0.000001

0.1

0.0001

The ADP 1995/2002


Equations

ADPi Abiotic Depletion Potential of resource i (-)

mi quantity of resource i extracted (kg)

i

ii mADPdepletionabiotic

The ADP 1995/2002


Equations

Ri ultimate reserve of resource I (kg);

DRi de-accumulation rate (extraction/production minus regeneration) of resource i (kg·yr-1)

Rref ultimate reserve of the reference resource, antimony (kg)

DRref de-accumulation rate of Rref (kg·yr–1)

The indicator result is expressed in kg of the reference (ref) resource, viz. antimony.

2

2

ref

ref

i

i

i

R

DR

R

DR

ADP Assumed 0 for

abiotic resources

The ADP 1995/2002


ADP 1995/2002: summary of choices

• Abiotic and biotic: separate impact categories

• Problem: decreasing availability of natural

resources

• Stocks (deposits)

• Renewable/non-renewable in modeling of CFs

• Concept: physical data on reserves & de-

accumulation

• „Narrow sense‟ availability

• Ultimate reserves

• Equation:

2

2

ref

ref

i

i

i

R

DR

R

DR

ADP

The ADP 1995/2002


Recent developments

• For latest ADPs:

http://cml.leiden.edu/software/data-cmlia.html

– correction of mistakes

– no data updates by CML after 2002; but update of

some DR and R data by Frischknecht et al. (2012)

– finally split up the ADP in two subcategories (fossil

fuels and minerals).

• Schneider et al. (2011) AADP and ESP

• Gemechu et al. (2015) GeoPolRisk

Recent developments





Substance cas no. group ADP kg antimony eq. / kg extraction 1,2,3

ultimate reserve4

reserve base reserve

aluminium (Al) 7429-90-5 element 1.09E-09 2.53E-05 2.14E-05 antimony (Sb) 7440-36-0 element 1.00E+00 1.00E+00 1.00E+00 arsenic (As) 7440-38-2 element 3.93E-03 2.40E+00 2.33E+00 barium (Ba) 7440-39-3 element 6.04E-06 3.37E-03 1.55E-02 beryllium (Be) 7440-41-7 element 1.26E-05 3.95E+00 bismuth (Bi) 7440-69-9 element 4.11E-02 4.49E+00 1.08E+01 boron (B) 7440-42-8 element 4.27E-03 5.28E-03 1.74E-02 bromine (Br) 7726-95-6 element 4.39E-03 cadmium (Cd) 7440-43-9 element 1.57E-01 1.11E+00 1.92E+00 chlorine (Cl) 7782-50-5 element 2.71E-05 chromium (Cr) 7440-47-3 element 4.43E-04 1.96E-05 3.77E-05 cobalt (Co) 7440-48-4 element 1.57E-05 2.56E-02 4.89E-02 copper (Cu) 7440-50-8 element 1.37E-03 2.50E-03 3.94E-03 gallium (Ga) 7440-55-3 element 1.46E-07 germanium (Ge) 7440-56-4 element 6.52E-07 1.95E+04 1.04E+04 gold (Au) 7440-57-5 element 5.20E+01 3.60E+01 3.99E+01 indium (In) 7440-74-6 element 6.89E-03 5.55E+02 1.15E+03 iodine (I2) 7553-56-2 element 2.50E-02 2.22E-03 3.10E-03 iron (Fe) 7439-89-6 element 5.24E-08 1.66E-06 3.64E-06 kalium (K;potassium)

7440-09-7 element 1.60E-08 9.00E-06 1.59E-05

lead (Pb) 7439-92-1 element 6.34E-03 1.50E-02 2.67E-02 lithium (Li) 7439-93-2 element 1.15E-05 1.33E-02 4.38E-02 magnesium (Mg) 7439-95-4 element 2.02E-09 manganese (Mn) 7439-96-5 element 2.54E-06 2.35E-05 5.80E-04

Result: updated CFs for different reserves

Source:

http://www.leidenuniv.nl/cml/ssp/projects/lca2/report_abiotic_depletion_web.pdf base year DR (extraction/de-accumulation) data: 1999 (USGS)

Recent developments

etc.

The reserve adopted may change the

decision-support provided Mineral reserve Mineral resource Crustal content


Reserve adopted may change results

product A Product B

aluminium (Al) 5 0

antimony (Sb) 0,1 0,2

arsenic (As) 0 0,5

barium (Ba) 0 3

beryllium (Be) 0,5 0

iron (Fe) 0 5

Inventory result

Crustal content Mineral resource Mineral reserve


Conclusions

• Impossible to define one correct method, since

correctness cannot be verified empirically

• Definition of the problem and all other choices

matter!!!

– other choices, and thus other methods, equally defensible

– “there‟s no such thing as the scientifically best method”

• Data ultimately extractable reserve will by definition

never be available

• CFs should be regularly updated, but are not!

– needs other „resources‟

Conclusions


(Non-scientific) consensus?

Conclusions

Most choices cannot be validated

by experimental data

Updated!!

Mining & metals

industry

Other

stakeholders

Abiotic and biotic

Problem: decreasing availability of natural

resources („depletion‟)

Stocks (not funds and flows)

Renewable/non-renewable in modelling CFs ? ?

Physical data on reserves & de-accumulation /

Narrow sense availability (not yet broad) / ?

Ultimate reserves (crustal content) ?

Equation for characterization factors ? ?

Undeservedly neglected so far

Increasing reserves (base and

economic), but decreasing crustal

content and extractable global resource

Independent of chosen stock?

Data update or „regeneration‟?

= “Opportunity Cost world

view”?

„Depletion‟ versus „accessibility,

presence or readiness of a resource for

human use‟

„Depletion‟ (environmental aspect; LCA)

only versus „accessibility, presence

readiness‟ (socio-economic aspects;

scarcity/criticality; weighting or LCSA) = “Fixed Stock world view”?

Depending on problem definition,

world view (narrow/broad sense)

etc.; all choices are mutually

dependent!


Why R2?

1. Share in reserves should also be assessed:

• Suppose a choice between applying 1 kg of resource A or 1 kg of

resource B, with following R and DR data:

– resource A: R=109 kg (and P=5×107 kg/yr)

– resource B: R=100 kg (and P=5 kg/yr).

– conclusion: A preferred, as R of A is affected far less by 1 kg extraction

• Now, suppose we adopt an equation R/DR (also known as R/P)

– R/DR of A and B is both 20 years

– resource A and B equally attractive in terms of depletion

2. Choice of units for ADP should not influence the final result for

abiotic depletion score

• Solution: Rz with z = y+1 and y>0 as reserve should be included

– R/DR method doesn‟t meet this requirement; see Guinée & Heijungs,

Environmental Toxicology & Chemistry (1995),14, 5, 917-925

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Abiotic Depletion Potential - · PDF fileLeiden University. The university to discover. Abiotic Depletion Potential - its philosophy from 1995 / 2002 – Jeroen Guinée Metals Industry